fix: Update metadata to include HLS granule ID and links to Fmask layer

[ceholden]

Description

This PR adds two extra pieces of metadata to the HLS-VI product metadata and addresses these tickets,

• Include HLS base granule ID in HLS-VI metadata file as an additional attribute #46
• include information on HLS Fmask layer in HLS-VI metadata #47

How I did it

• I added the original HLS granule ID as an <AdditionalAttribute> section
• I added two links (HTTP and S3) to the Fmask layer from the source HLS granule to the OnlineAccessURLs section. The links are well formed so we can simply construct the links based on the original HLS product granule ID.
• I ensured that the XML file was indented correctly before writing.
• I updated the test "golden (meta)data" with the outputs after manually verifying that it looked OK. I also tested one of the links to the Fmask layer and was able to download it ✅
• I updated the Granule.xsd to define the Input_GranuleUR and used the GranuleUR type as its type because both granule IDs should share the same validation (e.g., 1 <= length <= 250)
• Couple package changes,
  • Bumped lxml to latest so we can use the indent method and have an easier time installing it locally. This should also resolve 5 of the 7 Dependabot changes.
  • I also relaxed the NumPy pin to make it easier to compile locally
• Along the way my text editor caught a few typos

How you can test it

I updated the test "golden (meta)data" with these two metadata additions. You can run the metadata tests to compare against these by running,

pytest tests -k metadata

(the -k metadata scopes the run to just the metadata tests, which is nice because the other ones involve a lot of computation so take longer)

[ceholden]

I just noticed there was a PR to pin this but I don't know the backstory,
#34

It looks like there (shockingly) is a wheel for lxml==5.3.0 for py36, so maybe this is fine? I'm guessing the pin to an older version was to match the old version of the C library in our container. Maybe we can bump this to use the binary and then drop the libxml2-dev and libxslt1-dev?